Debugging the BPF Virtual Machine Lorenzo Fontana October 28, 2020 ● Debugging is useful to understand how things work ● Sometimes, eBPF programs can’t even load ● I couldn’t find good resources on this this, so, here I am ● I break lots of eBPF programs ● The BPF Virtual machine is not easy to understand Why ? The BPF subsystem lives in the kernel AND The kernel can be debugged using gdb The

3 Apache Virtual Host documentation 109 3.1 Apache Virtual Host documentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110 iii iv CONTENTS 3.2 Name-based Virtual Host Support . . . . . 111 3.3 Apache IP-based Virtual Host Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114 3.4 Dynamically Configured Mass Virtual Hosting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121 3.6 An In-Depth Discussion of Virtual Host Matching . . . . . . . . . . . . . . . . . . . . . . . . . . 129 3.7 File Descriptor Limits

auto-arranque do MC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 1.3.8 Virtual filesystem of MC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187 9.11.3 Montar o ficheiro de imagem de disco virtual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189 9.11.4 Sistema chroot . . . get back to the GUI environment, normally running on the virtual console 2, by pressing Alt-F2. You can alternatively change to another virtual console, e.g. to the console 3, from the commandline. #

administration tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.1.6 Virtual consoles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . MC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 1.3.8 Virtual filesystem of MC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179 9.11.3 Mounting the virtual disk image file . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179 9

configuration. Apache has the capability to serve many different websites simultaneously. This is called Virtual Hosting. Directives can also be scoped by placing them inside sections, so that they perfectly safe because this section will apply to all requests regardless of the specific URL. Virtual Hosts The container encloses directives that apply to specific hosts. This is useful hosts from the same machine with a different configuration for each. For more information, see the Virtual Host Documentation. Proxy The and containers apply enclosed configuration

configuration. Apache has the capability to serve many different websites simultaneously. This is called Virtual Hosting. Directives can also be scoped by placing them inside sections, so that they perfectly safe because this section will apply to all requests regardless of the specific URL. Virtual Hosts The container encloses directives that apply to specific hosts. This is useful hosts from the same machine with a different configuration for each. For more information, see the Virtual Host Documentation. Proxy The and containers apply enclosed configuration

configuration. Apache has the capability to serve many different websites simultaneously. This is called Virtual Hosting. Directives can also be scoped by placing them inside sections, so that they perfectly safe because this section will apply to all requests regardless of the specific URL. Virtual Hosts The container encloses directives that apply to specific hosts. This is useful hosts from the same machine with a different configuration for each. For more information, see the Virtual Host Documentation. Proxy The and containers apply enclosed configuration

configuration. Apache has the capability to serve many different websites simultaneously. This is called Virtual Hosting. Directives can also be scoped by placing them inside sections, so that they perfectly safe because this section will apply to all requests regardless of the specific URL. Virtual Hosts The container encloses directives that apply to specific hosts. This is useful hosts from the same machine with a different configuration for each. For more information, see the Virtual Host Documentation. Proxy The and containers apply enclosed configuration

3 Apache Virtual Host documentation 93 3.1 Apache Virtual Host documentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94 iii iv CONTENTS 3.2 Name-based Virtual Host Support . . . . . . 95 3.3 Apache IP-based Virtual Host Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98 3.4 Dynamically configured mass virtual hosting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105 3.6 An In-Depth Discussion of Virtual Host Matching . . . . . . . . . . . . . . . . . . . . . . . . . . 113 3.7 File Descriptor Limits

configuration. Apache has the capability to serve many different websites simultaneously. This is called Virtual Hosting. Directives can also be scoped by placing them inside sections, so that they perfectly safe because this section will apply to all requests regardless of the specific URL. Virtual Hosts The container encloses directives that apply to specific hosts. This is useful hosts from the same machine with a different configuration for each. For more information, see the Virtual Host Documentation. Proxy The and containers apply enclosed configuration